Low back pain due to superior cluneal nerve entrapment: A clinicopathologic study.

INTRODUCTION: We studied the clinical and nerve pathologic features in 6 patients whose low back pain (LBP) was relieved by superior cluneal nerve (SCN) neurectomy to determine whether nerve compression was the mechanism underlying this type of LBP. METHODS: All 6 patients (7 nerves) underwent SCN neurectomy for intractable LBP. Their clinical outcomes and the pathologic features of 7 nerves were reviewed. RESULTS: All patients reported LBP relief immediately after SCN neurectomy. Pathologic study of the 7 resected nerves showed marked enlargement, decreased myelinated fiber density, an increase in thinly myelinated fibers (n = 2), perineurial thickening (n = 5), subperineurial edema (n = 4), and Renaut bodies (n = 4). At the distal end of 1 enlarged nerve, we observed a moderate reduction in the density and marked reduction in the number of large myelinated fibers. DISCUSSION: The pathologic findings and effectiveness of neurectomy suggest that, in our patients, SCN neuropathy likely elicited LBP via nerve compression. Muscle Nerve 57: 777-783, 2018.

[Treatment Results of Low Back and Leg Pain Considering Para-Lumbar Spine Disease and Peripheral Nerve Neuropathy].

INTRODUCTION: Here we report our treatment results of low back and leg pain(LBLP)considering para-lumbar spine disease(PLSD)and peripheral nerve neuropathy(PNN). MATERIALS AND METHODS: We enrolled 103 patients who were admitted to our institute for LBLP treatment between January and December in 2014. For the treatment, we preferentially performed intensive block therapy for PLSD. RESULT: Among 103 patients, 89 patients had PLSD. In 85 patients, we performed intensive block therapy and 82 patients experienced short-term improvement of symptoms. In 35 of these 82 patients, lumbar spine and/or PNN surgical treatment was required as the effect of block therapy was transient. Intensive block therapy was effective in 47 of 103 patients(45.6%), and the remaining patients required surgical treatment(PLSD and/or PNN:31 cases, lumbar spine:13 cases, both:8 cases). CONCLUSION: Among 103 patients with LBLP, intensive block therapy for PLSD and PNN was useful for short-term symptom improvement in 82 patients(79.6%), and for long-term symptom improvement in 47 patients(45.6%)as evaluated at the final follow-up. Surgical treatment of PLSD and/or PNN was required in 39 patients(37.9%). These results suggested that treatment of PLSD and PNN might yield good results for patients with LBLP.

A Diagnostic Scoring System for Sacroiliac Joint Pain Originating from the Posterior Ligament.

Objective: Sacroiliac joint (SIJ) pain originating from the posterior ligament manifests in not only the buttocks but also the groin and lower extremities and thus may be difficult to discern from pain secondary to other lumbar disorders. We aimed to develop a simple clinical diagnostic tool to help physicians distinguish between patients with SIJ pain originating from the posterior ligament and those with lumbar disc herniation (LDH) or lumbar spinal canal stenosis (LSS). Design: Prospective case-control study. Patients and Methods: We evaluated 62 patients with SIJ pain originating from the posterior ligament and 59 patients with LDH and LSS. Pain areas, pain increasing positions, provocation test, and tenderness points were investigated. A scoring system based on multivariate logistic regression equations using the investigated items was developed. Results: Two pain areas (the posterosuperior iliac spine (PSIS) detected by the one-finger test and groin), pain while sitting on a chair, provocation test, and two tenderness points (PSIS and the sacrotuberous ligament) had high odds ratios (range, 25.87­1.40) and were used as factors in the scoring system. An integer score derived from the regression coefficient and clinical experience was assigned to each identified risk factor. The sum of the risk score for each patient ranged from 0­9. This scoring system had a sensitivity of 90.3% and a specificity of 86.4% for a positivity cutoff point of 4. Conclusion: The scoring system can help distinguish between patients with SIJ pain originating from the posterior ligament and those with LDH and LSS.

Decompression of the gluteus medius muscle as a new treatment for buttock pain: technical note.

PURPOSE: The clinical features and etiology of low back pain and buttock pain remain poorly understood. We report ten patients with buttock pain who underwent gluteus medius muscle (GMeM) decompression under local anesthesia. METHODS: Between December 2012 and November 2013 we surgically treated ten patients (four men, six women; mean age 65.1 years) for buttock pain. The affected side was unilateral in seven and bilateral in three patients (total sites, n = 13). The interval from symptom onset to treatment averaged 174 months; the mean postoperative follow-up period was 24 months. Decompression of the tight gluteal aponeurosis over the GMeM was performed under local anesthesia. Assessment of the clinical outcomes was on the numeric rating scale (NRS) for low back pain (LBP), the Japanese Orthopedic Association (JOA) score, and the Roland-Morris Disability Questionnaire (RDQ) score before and at the latest follow-up after treatment. RESULTS: There were no intraoperative surgery-related complications. The buttock pain of all patients was improved after surgery; their NRS decreased from 7.0 to 0.8 and JOA and RMDQ scores indicated significant improvement (p < 0.05). CONCLUSION: In patients with buttock pain, pain around the GMeM should be considered as a causative factor. Less invasive surgery with cutting and opening of the tight gluteal aponeurosis over the GMeM under local anesthesia yielded excellent clinical outcomes.

[Clinical feathers and treatment of peroneal nerve entrapment neuropathy].

OBJECTIVE: Peroneal nerve entrapment neuropathy (PEN) is generally known as a drop foot with sensory disturbance. However, some patients experience numbness and pain in the affected area without severe paresis due to PEN. We report the clinical features and our surgical results of PEN cases. METHODS: We encountered 17 cases of PEN. The patients were 7 females and 10 males and their ages ranged from 30 to 78 years(average 56.1 years). In these cases, conservative therapy was unsuccessful;therefore, we performed surgical treatment for PEN. RESULTS: Among the 17 cases, 4 were of bilateral and 13 were of unilateral PEN. There was no severe paresis, as in drop foot;however, mild paresis (4/5, manual muscle test, MMT) was noted in 15 cases. In all cases, intermittent claudication presented, which ranged from 10 to 800 m (average 150 m). In 13 cases, radiological abnormality of the lumbar region was noted and 8 cases had a history of lumbar surgery (they had failed back surgery syndrome). In all the cases, we performed neurolysis of the peroneal nerve under local anesthesia;there was no surgical complication. After the surgery, symptoms improved, and the numerical rating of the lower limb improved from 8.6/10 to 0.8/10. Intermittent claudication also improved in all of the cases. CONCLUSIONS: We successfully treated 17 cases of PEN, which had lower limb pain without severe paresis, as in drop foot. Our results indicate that PEN should be recognized as a cause of intermittent claudication. Neurolysis for PEN under local anesthesia is less invasive and is useful for the treatment of lower limb pain.

The impact of atherosclerotic factors on cerebral aneurysm is location dependent: aneurysms in stroke patients and healthy controls.

Previous studies have indicated that cerebrovascular diseases (CVDs) seem to increase the occurrence of unruptured intracranial aneurysms (UIAs). However, this maybe explained by the fact that CVDs and UIAs share common risk factors, such as hypertension (HT) and smoking. To clarify the impact of atherosclerotic risk factors on cerebral aneurysmal formation, we explored the incidence of UIAs and their locations in healthy controls and patients with CVD, who frequently have atherosclerotic risk factors. This study included consecutive 283 asymptomatic healthy adults and 173 acute stroke patients, from patients diagnosed with acute cerebral hemorrhage or cerebral infarction and admitted to our hospital. The incidence, maximum diameter, and location of UIAs were evaluated, and we also investigated the following factors: age, gender, current smoking, HT, diabetes mellitus (DM), and dyslipidemia. UIAs were found in 19 of the total 456 subjects (4.2%), 11 of 283 healthy subjects (3.9%), and 8 of 173 stroke patients (4.6%). These differences are not statically significant. The incidence of middle cerebral artery (MCA) aneurysms was significantly higher in the CVD patients than in the healthy controls (P = .03), and the incidence of paraclinoid aneurysms was significantly higher in the healthy controls than in the CVD patients (P = .03). Moreover, higher incidences of HTs and CVDs in the MCA aneurysms than in the other locations of UIAs were observed. These results indicate that the impact of atherosclerotic factors on cerebral aneurysmal formation depends on their location and that there is a stronger impact on MCA aneurysms than on paraclinoid aneurysms.

Treatment strategy for bilateral carotid stenosis: 2 cases of carotid endarterectomy for the symptomatic side followed by carotid stenting.

Since the introduction of carotid stenting (CAS), a combined treatment for bilateral lesions using carotid endarterectomy (CEA) and CAS has been developed. However, there has been only 1 report about CEA then CAS. Herein we describe 2 patients with bilateral severe carotid stenosis who were treated by CEA for the symptomatic side and CAS for the contralateral asymptomatic side. A 71-year-old man underwent CEA for the symptomatic side. Although the patient suffered hyperperfusion syndrome after CEA, he recovered fully after 3 weeks of rehabilitation. Two months later, CAS was performed for the asymptomatic side, and he was discharged with no deficit. A 67-year-old man underwent CEA for the symptomatic side. The patient developed no postoperative neurologic deficits except for hoarseness. Four weeks later, CAS was performed for the contralateral asymptomatic side. After the procedure, however, severe hypotension occurred, and treatment by continuous injection of catecholamine was necessary to maintain systematic blood pressure. The patient was ultimately discharged with no deficit. The combined therapy of CAS for the asymptomatic side and then CEA for the symptomatic side has been recommended by several authors. However, one of the problems of this strategy is the higher incidence of postprocedural hemodynamic complications, and hypotension after CAS may be dangerous for the symptomatic hemisphere. We suggest a combined therapy using CEA for the symptomatic side and then CAS for the asymptomatic side can be 1 beneficial treatment option for patients with bilateral carotid stenosis without coronary artery disease.

Impact of ageing on biological features of bone marrow stromal cells (BMSC) in cell transplantation therapy for CNS disorders: functional enhancement by granulocyte-colony stimulating factor (G-CSF).

This study was designed to clarify the effects of donor age on biological features of bone marrow stromal cells (BMSC), one of the candidates for cell transplantation therapy for CNS disorders, because many aged patients might require such therapy. This study was also aimed to test whether ex vivo treatments with granulocyte-colony stimulating factor (G-CSF) could modify biological properties of BMSC from aged donors and enhance its therapeutic effects in an animal model of traumatic brain injury. The BMSC were harvested from young (6-week-old) and aged (100-week-old) rats. The ageing significantly increased the senescence-associated ß-galactosidase (SA-ß-gal) activity of the cultured BMSC, and decreased their proliferative capacity and production of nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF). As the next step, the rats were subjected to brain freezing injury by applying liquid nitrogen onto the neocortex through the thinned skull. The 6-week BMSC, 100-week BMSC, G-CSF-treated 100-week BMSC or vehicle were stereotactically injected into the ipsilateral striatum at 7 days post-injury. Transplantation of the 6-week BMSC, but not 100-week BMSC, significantly improved locomotor function. However, treatment of the 100-week BMSC with 0.1 µmol of G-CSF significantly improved their proliferation activity and growth factor production, and recovered therapeutic effects in the injured brain. In conclusion, donor age may largely determine biological aspects of BMSC. G-CSF may contribute to improve the outcome of BMSC transplantation therapy for CNS disorders in aged patients.

Assessment of dysarthria with Frenchay dysarthria assessment (FDA-2) in patients with Duchenne muscular dystrophy.

PURPOSE: The purpose of this study was to test the psychometric properties of the Japanese version of Frenchay Dysarthria Assessment (FDA-2) and to use this tool to describe the features of speech in patients with Duchenne muscular dystrophy (DMD). MATERIALS AND METHODS: The Japanese version of FDA-2 was culturally adapted, and reliability and validity were examined in 22 and 50 patients, respectively. The Japanese version of FDA-2 was administered to 51 patients with DMD. Multiple regression analysis was performed to identify factors related to FDA-2 scores. RESULTS: Inter-/intra-rater reliabilities (ICCs) and internal consistency (Cronbach's α) for total scores were 0.76, 0.97, and 0.94 respectively. For construct validity, two-way ANOVA showed a significant interaction between the disorders and FDA-2 sections (p < 0.05). In DMD patients, the item of tongue at rest was most severely affected, reflecting tongue hypertrophy. Multiple regression analysis identified age, swallowing status, and ventilator use as significantly related. CONCLUSIONS: The results showed that the Japanese version of FDA-2 has satisfactory reliability and validity. The present study demonstrated the features of dysarthria and related factors in patients with DMD.Implications for rehabilitationIn Duchenne muscular dystrophy (DMD), an absent or defective dystrophin protein causes progressive weakness of respiratory and oropharyngeal muscles, both of which are crucial contributors to speech production.This study shows that the Japanese version of FDA-2 has satisfactory reliability and validity compared to original version.The Japanese version of FDA-2 characterizes dysarthria in patients with DMD in this cohort.

Intradural lumbar radicular arteriovenous malformation mimicking perimedullary arteriovenous malformation of the conus medullaris: illustrative case.

BACKGROUND: Intradural radicular arteriovenous malformation (AVM) of the cauda equina is a rare entity of spinal AVMs. Because of the specific arterial supply of the conus medullaris and cauda equina, AVMs in this area sometimes present with confusing radiological features. OBSERVATIONS: The authors reported a rare case of intradural radicular AVM arising from the lumbar posterior root. The patient presented with urinary symptoms with multiple flow void around the conus medullaris, as shown on magnetic resonance imaging. Digital subtraction angiography demonstrated arteriovenous shunt at the left side of the conus medullaris fed by the anterior spinal artery via anastomotic channel to the posterior spinal artery and rich perimedullary drainers. There was another arteriovenous shunt at the L3 level from the left L4 radicular artery. Preoperative diagnosis was perimedullary AVM with radicular arteriovenous fistula. Direct surgery with indocyanine green angiography revealed that the actual arteriovenous shunt was located at the left L4 posterior root. The AVM was successfully treated by coagulation of feeding branches. LESSONS: Unilateral arteriovenous shunt fed by either posterior or anterior spinal artery at the conus medullaris may include AVM of the cauda equina despite abundant perimedullary venous drainage. Careful pre- and intraoperative diagnostic imaging is necessary for appropriate treatment.

Secondary Chiari malformation due to enlarged spinal arachnoid villi-like structure: illustrative case.

BACKGROUND: Secondary Chiari malformation can be caused by various disorders associated with cerebrospinal fluid (CSF) leakage at the spinal level. In this report, the authors describe a rare case of secondary Chiari malformation caused by excessive CSF absorption through the enlarged spinal arachnoid villi-like structure. OBSERVATIONS: A 20-year-old woman presented with progressive severe headache and posterior neck pain. Magnetic resonance imaging showed tonsillar herniation and decreased subarachnoid space around the spinal cord. A hypointense signal area was observed in the ventral spinal canal on a T2-weighted image. An axial image revealed multiple small, arachnoid cyst-like structures at the right T1 nerve root sleeve. Direct surgery revealed that the cyst-like structures were continuous with the arachnoid membrane and protruded into the abnormally large epidural venous sinus. The cyst-like structures were resected, and the dural sleeve was repaired using fascia. The patient showed good improvement of symptoms after surgery. LESSONS: Excessive CSF absorption through the enlarged spinal arachnoid villi-like structure can cause secondary Chiari malformation. Neurosurgeons should be aware of this unusual mechanism of CSF leakage. Simple posterior fossa decompression will be ineffective or even harmful.

Pathophysiology and surgical treatment of spinal adhesive arachnoid pathology: patient series.

BACKGROUND: Spinal adhesive arachnoid pathology is a rare cause of myelopathy. Because of rarity and variability, mechanisms of myelopathy are unknown. The authors retrospectively analyzed patients to understand pathophysiology and provide implications for surgical treatment. OBSERVATIONS: Nineteen consecutive patients were studied. Thirteen patients had a secondary pathology due to etiological disorders such as spinal surgery or hemorrhagic events. They received arachnoid lysis (4 patients), syringo-subarachnoid (S-S) shunt (8 patients) with or without lysis, or anterior decompression. Three of them developed motor deterioration after lysis, and 6 patients needed further 8 surgeries. Another 6 patients had idiopathic pathology showing dorsal arachnoid cyst formation at the thoracic level that was surgically resected. With mean follow-up of 44.3 months, only 4 patients with the secondary pathology showed improved neurological grade, whereas all patients with idiopathic pathology showed improvement. LESSONS: The idiopathic pathology was the localized dorsal arachnoid adhesion that responded to surgical treatment. The secondary pathology produced disturbed venous circulation of the spinal cord by extensive adhesions. Lysis of the thickened fibrous membrane with preservation of thin arachnoid over the spinal veins may provide safe decompression. S-S shunt was effective if the syrinx extended to the level of normal subarachnoid space.

Synergistic effects of bone marrow stromal cells and a Rho kinase (ROCK) inhibitor, fasudil on axon regeneration in rat spinal cord injury.

Transplanted bone marrow stromal cells (BMSC) promote functional recovery after spinal cord injury (SCI) through multiple mechanisms. A Rho kinase inhibitor, Fasudil also enhances axonal regeneration. This study was aimed to evaluate whether combination therapy of BMSC transplantation and Fasudil further enhances axonal regeneration and functional recovery in rats subjected to SCI. Fasudil or vehicle was injected for 2 weeks. BMSC or vehicle transplantation into the rostral site of SCI was performed at 7 days after injury. Neurological symptoms were assessed throughout the experiments. Fluoro-Ruby was injected into the dorsal funiculus of the rostral site of SCI at 63 days after injury. The fate of the transplanted BMSC was examined using immunohistochemistry. BMSC transplantation significantly increased the number of Fluoro-Ruby -labeled fibers of the dorsal corticospinal tracts at the caudal site of SCI, enhancing functional recovery of the hind limbs. Some of the engrafted BMSC were positive for Fluoro-Ruby, neuronal specific nuclear protein and microtubule-associated protein-2, suggesting that they acquired neuronal phenotypes and built synaptic connection with the host's neural circuits. Fasudil treatment also improved axonal continuity, but did not promote functional recovery. Combination therapy dramatically increased the number of Fluoro-Ruby-labeled fibers of the dorsal corticospinal tracts at the caudal site of SCI, but did not further boost the therapeutic effects on locomotor function by BMSC transplantation. The findings suggest that BMSC transplantation and Fasudil provide synergistic effects on axon regeneration after SCI, although further studies would be necessary to further enhance functional recovery.

Bone marrow stromal cells and bone marrow-derived mononuclear cells: which are suitable as cell source of transplantation for mice infarct brain?

There are few studies that denote whether bone marrow stromal cells (BMSC) and bone marrow-derived mononuclear cells (MNC) show the same therapeutic effects, when directly transplanted into the infarct brain. This study therefore aimed to compare their biological properties and behaviors in the infarct brain. Mouse BMSC were harvested and cultured. Mouse MNC were obtained through centrifugation techniques. Their cell markers were analyzed with FACS analysis. The MNC (10(6) cells; n = 10) or BMSC (2 x 10(5) cells; n = 10) were stereotactically transplanted into the ipsilateral striatum of the mice subjected to permanent middle cerebral artery occlusion at 7 days after the insult. Their survival, migration, and differentiation in the infarct brain were precisely analyzed using immunohistochemistry 4 weeks after transplantation. The MNC were positive for CD34, CD45, CD90, but were negative for Sca-1. The BMSC were positive for CD90 and Sca-1. The transplanted BMSC, but not MNC, extensively migrated into the peri-infarct area. Approximately 20% of the transplanted BMSC expressed a neuronal marker, NeuN in the infarct brain, although only 1.4% of the transplanted MNC expressed NeuN. These findings strongly suggest that there are large, biological differences between MNC and BMSC as cell sources of regenerative medicine for ischemic stroke.

Synergistic effects of granulocyte-colony stimulating factor on bone marrow stromal cell transplantation for mice cerebral infarct.

This study was aimed to assess whether ex vivo treatment with granulocyte-colony stimulating factor (G-CSF) modifies biological properties of bone marrow stromal cells (BMSC) and enhances functional recovery by BMSC transplantation into infarct brain. Immunohistochemistry was conducted to characterize the cultured BMSC. The pharmacological effects of G-CSF on their proliferation, cell cycle, and growth factor production were precisely analyzed, using FACS and ELISA techniques. Non-treated or G-CSF treated BMSC were stereotactically transplanted into the mice brain subjected to cerebral infarct, and its effects on functional and histological aspects were evaluated. The BMSC expressed the receptor for G-CSF. Treatment with 0.1muM of G-CSF significantly enhanced the proliferation of BMSC by increasing their population in S phase, and increased their production of SDF-1alpha, HGF, and NGF. When transplanted into infarct brain, G-CSF treated BMSC significantly improved motor function as early as 2 weeks after transplantation, whereas non-treated BMSC did 4 weeks after transplantation. These findings strongly suggest that G-CSF may enhance the proliferation and growth factor production of the cultured BMSC and accelerate functional restoration by BMSC transplantation. Such pharmacological "activation" of the BMSC may contribute to successful clinical application of BMSC transplantation therapy for ischemic stroke.

Graded model of diffuse axonal injury for studying head injury-induced cognitive dysfunction in rats.

Diffuse axonal injury (DAI) plays a major role in the development of cognitive dysfunction, emotional difficulties and behavioral disturbances in patients following closed head injury, even when they have no definite abnormalities on conventional MRI. This study aimed to develop a highly controlled and reproducible model for DAI that simulates post-traumatic cognitive dysfunction in humans. Sprague-Dawley (SD) rats were subjected to impact acceleration head injury, using a pneumatic impact targeted to a steel disc centered onto their skull. The severity of injury was graded as three levels by adjusting the driving pressure at 60, 70 or 80 pounds per square inch. In vivo MRI was obtained 2 days post-injury. Cognitive function was evaluated using the Morris water maze at 1 and 2 weeks post-injury. HE staining and immunohistochemistry were performed to assess neuronal and axonal damages after 2 weeks. MRI demonstrated that this model induced no gross structural modification in the brain. The degree and duration of cognitive dysfunction were dependent on the force of impact. Histological analysis revealed the force-dependent damage of the neurons and microtubule-associated protein 2-positive axons in the neocortex. Hippocampal damage was much less pronounced and was not linked to cognitive dysfunction. This is the first report that precisely evaluates the threshold of impact energy to lead to neocortical damage and cognitive dysfunction in rodents. This model would be suitable for clarifying the complex mechanisms of post-traumatic brain damage and testing novel therapeutic approaches against post-traumatic cognitive dysfunction due to diffuse axonal damage.

Transplanted bone marrow stromal cells improves cognitive dysfunction due to diffuse axonal injury in rats.

Diffuse axonal injury (DAI) often leads to persistent cognitive dysfunction in spite of the lack of gross lesions on MRI. Therefore, this study was aimed to evaluate whether transplanted bone marrow stromal cells (BMSC) can improve DAI-induced cognitive dysfunction or not. The rats were subjected to impact acceleration head injury, using a pneumatic high-velocity impactor. The BMSC were harvested from the mice and were cultured. The BMSC (4.0 x 10(5) cells) or vehicle were stereotactically transplanted into the right striatum at 10 days post-injury. Cognitive function analysis was repeated at 1, 2, and 4 weeks post-injury, using the Morris water maze test. Histological analysis was performed at 2, 8 and 20 weeks post-injury, using double fluorescence immunohistochemistry. Transplanted BMSC were widely distributed in the injured brain and gradually acquired the phenotypes of neurons and astrocytes over 20 weeks. In addition, they significantly improved DAI-induced cognitive dysfunction as early as 2 weeks post-injury, although their processes of neuronal differentiation were not completed at this time point. The findings suggest that the engrafted BMSC may exhibit this early beneficial effect on cognitive function by producing neuroprotective or neurotrophic factors. In conclusion, direct transplantation of BMSC may serve as a novel therapeutic strategy to enhance the recovery from DAI-induced cognitive impairment.

Treatment of low back pain elicited by superior cluneal nerve entrapment neuropathy after lumbar fusion surgery.

OBJECT: Low back pain (LBP) attributable to fusion failure, implant failure, infection, malalignment, or adjacent segment disease may persist after lumbar fusion surgery (LFS). Superior cluneal nerve (SCN) entrapment neuropathy (SCNEN) is a clinical entity that can produce LBP. We report that SCNEN treatment improved LBP in patients who had undergone LFS. METHODS: Between April 2012 and August 2015, we treated 8 patients (4 men and 4 women ranging in age from 38 to 88 years; mean age, 69 years) with SCNEN for their LBP after LFS. Our criteria for the diagnosis of SCNEN included a trigger point over the posterior iliac crest 7 cm from the midline and numbness and radiating pain in the SCN area upon compression of the trigger point. Symptom relief was obtained in more than 75% of patients within 2 h of inducing a local nerve block at the trigger point in the buttocks. The mean postoperative follow-up period was 28 months (range, 9-54 months). RESULTS: LBP was unilateral in 3 and bilateral in 5 patients. The senior author (T.I.) operated all patients for SCNEN under local anesthesia because they reported recurrence of pain after the analgesic effect of repeat injections wore off. This led to a significant improvement of their LBP. CONCLUSIONS: SCNEN should be considered in patients reporting LBP after LFS. Treatment of SCNEN may be a useful option in patients with failed back surgery syndrome after LFS.

Long-term Outcome of Surgical Treatment for Superior Cluneal Nerve Entrapment Neuropathy.

STUDY DESIGN: Prospective observational cohort study. OBJECTIVE: The objective of this study was to present the long-term surgical outcomes of operative treatment for superior cluneal nerve (SCN) entrapment neuropathy (SCNEN) and to analyze the causes of poor results and further treatment required. SUMMARY OF BACKGROUND DATA: There are a few reports of the outcomes of surgical treatment for SCNEN, and most studies describe results for operations conducted under general anesthesia with short follow-up periods. METHODS: Surgery was performed for SCNEN in 52 consecutive patients on 79 sides, excluding patients who had undergone previous surgery on the lumbar spine. Entrapment was unilateral in 25 patients and bilateral in 27. The mean postoperative follow-up period was 41.3 months (range, 29-58 months). All patients had received conservative treatment without improvements, and operations were performed under local anesthesia. RESULTS: Twenty-three cases (44%) involved only low-back pain (LBP), and 31 cases (60%) involved LBP associated with leg numbness or pain. The mean number of SCN branches decompressed in the operative field at the first operation was 1.4 (range, 1-4 branches). There were no local or systemic complications during or after the operation. All patients reported symptom improvement, but LBP caused by SCNEN recurrence was reported for 10 sides (13%) in seven patients who subsequently underwent repeat surgery. In the second surgery, the number of additionally treated SCN branches was 2.0 (range, 1-5). Additional surgeries were performed in two cases for lumbar disorders. All patients showed significant improvement at the last follow-up visit (P < 0.05), including those who developed recurrence. CONCLUSION: Long-term outcomes of surgical treatment for SCNEN were satisfactory. For prevention of recurrence, as many SCN branches as possible should be decompressed in the operation field during the first operation. LEVEL OF EVIDENCE: 4.

[Motor cortex stimulation for post-stroke pain using neuronavigation and evoked potentials: report of 3 cases].

Although motor cortex stimulation (MCS) has been accepted as an effective therapeutic option for central pain, the efficacy of MCS widely varies among previous reports. In this report, we describe our recent trial for successful MCS in 3 patients with central pain due to cerebral stroke. Medical treatments were transiently effective, but gradually became ineffective in all of the cases. During surgery, the appropriate cortical target was determined by using neuronavigation, somatosensory evoked potential (SEP), and motor evoked potential (MEP). A flat, four-plate electrode was positioned on the dura mater parallel to the motor cortex. After surgery, pain almost resolved in 2 of 3 patients and markedly improved in another. The pain relief depended on their motor function. These findings strongly suggest that both patient selection and intraoperative monitoring for targeting the motor cortex are quite important for successful MCS, although further studies were essential.